174848-61-4Relevant articles and documents
Palladium-catalyzed enantioselective oxidation of alcohols: a dramatic rate acceleration by Cs2CO3/t-BuOH.
Bagdanoff, Jeffrey T,Ferreira, Eric M,Stoltz, Brian M
, p. 835 - 837 (2003)
[reaction: see text] The addition of Cs(2)CO(3) and t-BuOH provides a dramatic rate acceleration in the palladium-catalyzed aerobic oxidative kinetic resolution of secondary alcohols while maintaining the selectivity of the process.
Kinetic resolution of allylic alcohols using a chiral phosphine catalyst
Vedejs, Edwin,MacKay, James A.
, p. 535 - 536 (2001)
(Matrix presented) The kinetic resolution of racemic allylic alcohols 3, 6, and 12-17 has been explored using the PBO catalyst 7 for activation of isobutyric anhydride. Trisubstituted allylic alcohols (12-15; 17) are the best substrates and react with an enantioselectivity of s = 32-82 at -40°C.
Copper-catalysed enantioselective stereodivergent synthesis of amino alcohols
Shi, Shi-Liang,Wong, Zackary L.,Buchwald, Stephen L.
, p. 353 - 356 (2016)
The chirality, or 'handedness', of a biologically active molecule can alter its physiological properties. Thus it is routine procedure in the drug discovery and development process to prepare and fully characterize all possible stereoisomers of a drug can
Allylic alcohols of unexpected confirugation by oxazaborolidine-catalysed reduction of α,β-unsaturated ketones. An explanation based on MO calculations
Bach,Berunguer,Farras,Garcia,Meseguer,Vilarrasa
, p. 2683 - 2686 (1995)
While the reduction of most α,β-unsaturated ketones with BH3:SMe2 in the presence of (R)-B-methyl-4,5,5-triphenyl-1,3,2-oxazaborolidine [(R)-2] affords allylic alcohols of the S configuration, that of α,β-unsaturated ketones branched
Asymmetric Reduction of αβ-Unsaturated Ketones with Lithium Aluminium Hydride Partially Decomposed by (-)-N-Methylephedrine and N-Ethylaniline
Terashima, Shiro,Tanno, Norihiko,Koga, Kenji
, p. 1026 - 1027 (1980)
The title asymmetric reaction is found to convert open chain enones into the corresponding optically active allylic alcohols in high optical (78-98percent enantiomeric excess) and chemical (92-100percent) yields.
Highly Active Cooperative Lewis Acid—Ammonium Salt Catalyst for the Enantioselective Hydroboration of Ketones
Titze, Marvin,Heitk?mper, Juliane,Junge, Thorsten,K?stner, Johannes,Peters, René
supporting information, p. 5544 - 5553 (2021/02/05)
Enantiopure secondary alcohols are fundamental high-value synthetic building blocks. One of the most attractive ways to get access to this compound class is the catalytic hydroboration. We describe a new concept for this reaction type that allowed for exceptional catalytic turnover numbers (up to 15 400), which were increased by around 1.5–3 orders of magnitude compared to the most active catalysts previously reported. In our concept an aprotic ammonium halide moiety cooperates with an oxophilic Lewis acid within the same catalyst molecule. Control experiments reveal that both catalytic centers are essential for the observed activity. Kinetic, spectroscopic and computational studies show that the hydride transfer is rate limiting and proceeds via a concerted mechanism, in which hydride at Boron is continuously displaced by iodide, reminiscent to an SN2 reaction. The catalyst, which is accessible in high yields in few steps, was found to be stable during catalysis, readily recyclable and could be reused 10 times still efficiently working.
Control of Chemo-, Regio-, and Enantioselectivity in Copper Hydride Reductions of Morita-Baylis-Hillman Adducts
Linstadt, Roscoe T. H.,Peterson, Carl. A.,Jette, Carina I.,Boskovic, Zarko V.,Lipshutz, Bruce H.
, p. 328 - 331 (2017/04/21)
Nonracemically ligated copper hydride can be used to effect tandem SN2′/1,2-reductions of racemic Morita-Baylis-Hillman (MBH) acetates to access enantioenriched chiral allylic alcohols with defined olefin geometry. MBH esters, including those w
Iridium-catalyzed asymmetric hydrogenation of α-substituted α,β-unsaturated acyclic ketones: Enantioselective total synthesis of (-)-mesembrine
Zhang, Qian-Qian,Xie, Jian-Hua,Yang, Xiao-Hui,Xie, Jian-Bo,Zhou, Qi-Lin
supporting information, p. 6158 - 6161 (2013/02/23)
A highly efficient asymmetric hydrogenation of α-substituted α,β-unsaturated acyclic ketones catalyzed by chiral spiro iridium complexes for the preparation of chiral 2-substituted allylic alcohols has been developed (ee up to 99.7%). This method provides a concise route to (-)-mesembrine (34% yield, 12 steps).
Enantioselective addition of dimethylzinc to aldehydes catalyzed by a chiral perhydro-1,3-benzoxazine-based amino alcohol as ligand
Infante, Rebeca,Nieto, Javier,Andrs, Celia
experimental part, p. 1343 - 1348 (2012/06/30)
Dimethylzinc undergoes efficient enantioselective addition to a wide variety of aromatic and aliphatic aldehydes in the presence of a catalytic amount of a chiral perhydro-1,3-benzoxazine-based amino alcohol. Methyl carbinols are obtained in good yields and in enantiomeric excesses of 99% or more in the absence of any metal other than zinc. Georg Thieme Verlag Stuttgart · New York.
Synthetic approach toward cis-disubstituted γ- And δ-lactones through enantioselective dialkylzinc addition to aldehydes: Application to the synthesis of optically active flavors and fragrances
Pisani, Laura,Superchi, Stefano,D'Elia, Alessandra,Scafato, Patrizia,Rosini, Carlo
experimental part, p. 5779 - 5784 (2012/09/08)
A versatile and straightforward approach to optically active cis-4,5-disubstituted γ- and δ-lactones by catalytic enantioselective addition of dialkyzincs to cinnamic aldehydes and RCM ring closure has been reported. The synthetic importance of the enantioselective dialkylzinc alkylation of aldehydes has been thus widened. Such an approach has then been employed for the enantioselective synthesis of naturally occurring γ-lactone flavors like (S)-5-ethyl-butanolide (6a) and (4S,5S)-cis-whisky lactone (6b) and extended to the preparation of δ-lactones like (5S,6S)-5-methyl-6-ethylpentanolide (9a), precursor of the pheromone serricornin.
